On Tue, Jan 9, 2018 at 4:09 PM, Kumar, Virendra <Virendra.Kumar@xxxxxxxxxxx> wrote: > It did not seem to help. > See attachment. Yeah while it's still writing, it's about half as much but most of the time seems to be in merging etc multiple data sets. I'm wondering what non-default values you might have set otherwise. Are you running on SSDs? If so lowering random_page_cost might help, but again, this might just be a very expensive query as well.